Lubricating oil composition



Dec. 21, 1948. A. FARKAs Erm.

LUBRICATING OIL COMPOSITION Filed Aug. 16, 1943 Patented Dec. 2l, 1948 LUBRICATING OIL COMPOSITION Adalbert Farkas and Arthur F. Stribley, Jr., Long Beach. Calif., assignors to Union Oil Company of California, Los Angeles, Calif., a corporation of California Application August 16, 1943, Serial No. 498,776

3 Claims.

This invention relates to partial oxidation products and methods of producing such products from hydrocarbons or hydrocarbon oils, such as petroleum and petroleum fractions. The invention also relates to alcohols and/or ketones and to methods of producing such alcohols and/or ketones from non-aromatic cyclic hydrocarbons. The invention also relates to polyvalent metal salts of phosphate esters of the partial oxidation oi hydrocarbons or hydrocarbon fractions and to lubricating oil compositions containing these metal salts.

An object of the present invention is to further the progress in preparing oxygenated hydrocarbon derivatives from hydrocarbons or hydrocarbon fractions, using in this case a method which limits the extent of oxidation thereby limiting the number and complexity of oxygenated products thus allowing the more ready segregation of the oxygenated derivatives into pure compounds.

Another object of the invention is to prepare from a single hydrocarbon or from a given hydrocarbon fraction, such as a relatively narrow boiling range hydrocarbon fraction prepared from petroleum, cyclic and/or acyclic alcohols and ketones With a minimum production of the more highly oxidized products, such as aldehydes, acids, hydroxy acids, etc., and ultimate oxidation products such as water and carbon dioxide.

A further object of the invention is to provide a method for producing alcohols and/or ketones in substantial quantities from hydrocarbons.

A further object of our invention is to prepare cyclic and/or acyclic alcohols and ketones having five or more carbon atoms per molecule from nonaromatic cyclic hydrocarbons, Whether used alone or mixed with acyclic or aromatic hydrocarbons boiling at or near the same temperature as the non-aromatic cyclic hydrocarbons, by a process involving oxidation With oxygen, air, or other oxygen-containing gas.

lA particular object of our invention is to prepare a lubricating oil addition agent and to prepare a lubricating oil composition comprising a major proportion of a lubricating oil and a minor proportion of an addition agent, said addition agent being a polyvalent metal salt of the reaction product of phosphorus pentasulde or phosphorus pentoxide and the cyclic and/or acyclic alcohols produced by partial oxidation of hydrocarbons.

Other objects, features and advantages of our invention Will be apparent to those skilled in the art as vthe description thereof proceeds and from the examples submitted herein.

The invention comprises oxidizing a hydrocarcon or a relatively narrow boiling range hydrocarbon fraction in the liquid phase and under conditions such that only partial oxidation occurs,

the partial oxidation products being removed continuously by processes involving fractional distillation, extractive distillation, azeotropic distillation, solvent extraction or adsorption from the slightly oxidized hydrocarbon or hydrocarbon fraction at such a rate that only minor proportions of these primary oxidation products are further oxidized, thus permitting-the production of relatively high yields of partial oxidation products.

The invention also comprises separating the products oi' partial oxidation into substantially pure compounds or into fractions comprising alcohols or ketones by relatively simple processes involving physical and/or chemical treatments, the particular method employed in a given case depending upon the character and the complexity of the oxygenated products to be separated.

The invention further comprises converting said partial oxidation products into lubricating oil addition agents and blending said addition agents with lubricating oil to produce lubricating oil compositions having improved iilm strength, anticorrosion and detergency characteristics.

Alcohols and ketones having ve or more carbon atoms per molecule are particularly valuable products. The ketones are used in the synthesis of chemicals and perfumes, as solvents ior lacquers, gums, resins, nitrocellulose, etc., and for the production of alcohols. The alcohols have use in perfumes, as antifoaming agents, as solvents for dyestuis, oils, waxes, gums, resins, etc., in the production of esters, acids, etc., as emulsifying agents, and in textile linishing compositions. Also alcohols produced by our oxidation process may be reacted with phosphorus pentasulde to form the corresponding dialkyl thiophosphates and the products of this reaction may then be reacted with metals or metal oxides vto form the corresponding metallic salts of the dialkylthiophosphates and/or dicycloalkylthiophosphates and'these compounds are excellent lubricating oil additives. When blended with mineral lubricating oils in amounts in the order of from about 0.1% to about 10% or more the metal dialkylthiophosphates impart high film strength to the oil, they improve the stability of the oil toward oxidation, reduce bearing corrosion in an engine and, when used in conjunction with other additives having detergency characteristics, they markedly increase the detergency of the lubricating oil blends containing the latter additives. Such other additives, which may be employed in amounts in the order of from about 0.1% to about 5.0% of the iinished lubricating oil composition, may be oil-soluble polyvalent metal soaps of various carboxylic acids, such as phenylated carboxylic acids, e. g., calcium phenyl stearate and magnesium phenylstearate, chlorinated and phenylated fatty acids, e. g., calcium dichlorophenylstearate and zinc dichlorophenylstearate; oil soluble polyvalent metal salts of oilsoluble petroleum sulfonic acids, such as the calcium salts of the oil-soluble sulfonic acids prepared by treating petroleum oils, such as lubricating oil, with strong sulfuric acid. Other oilsoluble polyvalent metal salts of these acids may also be used, such as those in which the metals may be strontium, barium, magnesium, zinc. manganese, aluminum, and lead.

Lubricating oils which may be blended with our organic phosphate addition agent, or with our agent together with one of the above disclosed other additives having detergency characteristics, include all minerallubricating oils because we nd that the valuable characteristics of our addition agent are imparted to all mineral lubricating oils. We prefer to employ treated oils such as acid refined Western lubricating oils, highly solvent refined Western lubricating oils or we may use Eastern lubricating oils such as Pennsylvania oils. The alcohols which may be prepared by the partial oxidation of hydrocarbons and which may be employed to produce desirable lubricating oil additives when treated in the above manner include the cycloaliphatic alcohols containing from five to about twelve carbon atoms and preferably seven to ten carbon atoms per molecule and the acyclic aliphatic alcohols containing from seven to about eighteen carbon atoms and preferably eight to fourteen carbon atoms per molecule.

The lubricating oil additives may be prepared by heating and agitating a mixture of 4 gram moles of the alcohol with 1 gram mole of phosphorus Pentasulde at a temperature of 250 F. to 300 F. until the P255 is completely dissolved, indicating that it has reacted completely with the alcohol and the product of thisreaction is maintained at the same temperature and agitated with 1 gram mole of an oxide vof one of the polyvalent metals disclosed hereinabove or with one gram atom of the polyvalent metal itself to form the metal salt of the thiophosphate ester. The first reaction results in the formation of relatively large proportions of the dialkyl or dicycloalkyl thiophcsphates represented by the following formula in which R represents the hydrocarbon radical of the alcohol:

su s=PoR It is known that other acid thiophosphate esters are produced by the above reaction but their presence in the reaction mixture apparently does not degrade the quality of lubricating oil additives prepared from this mixture. Formulas for the other esters which are present in the reaction product of an alcohol and phosphorus pentasulflde in relatively small proportions are:

Phosphorus pentoxide may be used in place of the phosphorus pentasulfide in the production of lubricating oil addition agent and in this case the oxyphosphate esters are formed. Thus 4 moles of an aliphatic or cycloaliphatic alcohol may be reacted with one mole of phosphorus pentoxide to produce the corresponding dialkyl or dicycloalkyl phosphates. These phosphate esters may then be reacted with one of the above disclosed polyvalent metals or with an oxide of one of these metals to form the corresponding polyvalent metal salt of the dialkyl or dicycloalkyl phosphates.

Alcohols which are useful for the above purposes are in general dimcult and costly to produce, their preparation requiring the use of expensive chemical processes. We find that we may produce alcohols. both cyclic and acyclic, containing five or more carbon atoms per molecule by a relatively inexpensive and simple process involving partial oxidation of certain hydrocarbons cr hydrocarbon fractions, separating the products of partial oxidation from the unoxidized hydrocarbon and subsequently segregating the partial oxidation products into fractions consisting primarily oi' alcohols 'and ketones. The ketones. if desired, may be subsequently converted into the corresponding alcohols as indicated hereinbelow.

In carrying out the production of partial oxidation products according to the principles of our invention. the hydrocarbon or narrow boiling range hydrocarbon fraction to be oxidized la blownwith oxygen, air, or other oxygen-containing gas until the proportion of hydrocarbon molecules oxidized is about 0.1% to about 10% or preferably about' 0.5% to about 5.0% of the total molecules present and the concentration of oxygenated molecules is thereafter maintained at an approximately constant value by continuously withdrawing portions of the slightly oxidized hy drocarbon material present in the oxidation vessel, separating the oxygenated molecules from the unoxidized hydrocarbon material, as by fractional distillation, and returning the latter material to the oxidation unit together with sufficient additional feed to maintain an approximately constant level in this vessel. The volatile materials, such as any oxygenated degradation products. pass out of the unit with spent air or other gaseous oxidizing medium. This operation involving the separation of oxidation products from unoxidized hydrocarbons can be considered to be a stripping operation.

Although we may treat any hydrocarbon or narrow boiling hydrocarbon fraction we prefer to employ a non-aromatic cyclic hydrocarbon, or a narrow boiling range hydrocarbon fraction, containing at least one non-aromatic cyclic hydrocarbon. Thus, hydrocarbons which maybe used as feed include cyclopentane or any of the mono. di, tri, tetra, or p'enta alkylcyclopentanes, such as methylcyclopentane, dlmethylcyclopentane,

methylethylcyclopentane, etc.; cyclohexane or.

any of the mono, di. tri. tetra, penta, or hexa alkylcyclohexanes, such as methylcyclohexane, dimethylcyclohexane, diethylcyclohexane, etc.; naphthenyl cyclopentanes or cyclohexanes containing one or more naphthenyl groups, such as bicyclopentane, bicyclohexane and alkyl substituted bicyclopentanes and bicyclohexanes, such as methylbicyclopentane and methylbicyclohexane; hydro aromatics, such as decahydronaphthalene and alkyl substituted hydro aro-- matics, such as methyldecahydronaphthalene. Mixtures of two or more of the above disclosed naphthene hydrocarbons may be employed as feed if desired when such mixtures have boiling ranges not wider than about 50 F. and preferably not wider than about 10 F. Also hydrooarbon fractions containing at least one of the above disclosed naphthene hydrocarbons together with non-naphthenic hydrocarbons, such as for ex ample, parains or oleiins or aromatics, or mix tures of these non-naphthenic hydrocarbons may be treated according to our invention. Such fractions should have a boiling range not wider than about 50 F. and preferably not wider than about F.

Other hydrocarbons which may desirably be treated by our process include the cycloolen hydrocarbons and the naphthene hydrocarbons containing olenic substituents, narrow boiling range mixtures of the oleiinic cyclic hydrocarbons or narrow boiling range fractions containing one or more of these olefinic cyclic hydrocarbons. Thus we may employ cyclopentene and the cyclopentadiene and the mono, di, tri, etc., alkyl cyclopentenes and cyclopentadienes, cyclohexene and cyclohexadiene and the mono, di, tri, etc., alkyl cyclohexenes and cyclohexadienes; mixtures of these hydrocarbons when such mixtures have boiling ranges not wider than about 50 F. and preferably not wider than about 10 F.; hydrocarbon fractions containing one or more of the above mentioned cycloolefins or cyclodioleiins together with one or more dissimilar hydrocarbons, such as paraihns, naphthenes, oleiins and aromatics; alkenyl substituted cyclopentanes and cyclohexanes, such as ethenylcyclopentane, ethenycyclohexane, etc.; alkenyl substituted mono, di, tri, etc., alkyl cyclopentanes and cyclohexanes, such as methylethenylcyclopentane, dirnethylethenylcyclohexanes, etc.; mixtures of such alkenyl substituted cyclopentanes, cyclohexanes, alkyl cyclopentanes and alkyl cyclohexanes; and hydrocarbon fractions containing at least one of the all-:enyl derivatives, such mixtures or fractions having relatively narrow boiling ranges as specied hereinabove for mixtures or fractions suitable for treatment in our process.

Although, as indicated hereinabove, We may treat a hydrocarbon mixture or fraction comprising at least one non-aromatic cyclic hydrocarbon together with paraiiin, olefin and aromatic hydrocarbons boiling at or near the boiling point of the non-aromatic cyclic hydrocarbon, it is preferable to remove substantially all of the aromatic hydrocarbons before carrying out said treatment. Methods for separating and/or removing the aromatic hydrocarbons from such mixtures include azeotropic distillation, solvent extraction, extractive distillation and, in the case of hydrocarbons Vfractions which do not contain cycloolen hydrocarbons, sulfuric acid treatment may be employed. rIhe methods of effecting azeotropic distillation extractive distillation and solvent extraction and the azeotrope formers or solvents which may be employed are disclosed hereinbelow.

Alcohols and ketones which may be producedr by our process include the cycloaliphatic and ali hexenone; the various mono, di, tri, etc., alkyl n substituted cycloolenic alcohols and ketones, such as for example, the various isomeric methylcyclopentenols, methylcyclohexenols, methylcyclopentenones, methylcyclohexenones, and higher homologs of these compounds; the alkenyl cycloaliphatlc alcohols and ketones, such as ethenylcyclopentanol, ethenylcyclohexanol, ethenylcyclopentanone and ethenylcyclohexanone and the higher homologs of these compounds, such as the isomeric methylethenylcyclohexanols, methylethenylcyclohexanones, ethylpropenylcyclopentanol, etc.` The aliphatic alcohols and ketones which may be produced by our process include pentanol, pentanone, the various isomeric methyland ethyl-pentanols and pentanones, hexanol and hexanone, the isomeric methyl, ethyl-, propyl, and isopropyl-hexanols and hexanones; dialkylpentanols, pentanones, hexanols. and hexanones and higher homologs of these compounds such as trimethylhexanol, dimethylethylhexanone, etc. Olenic alcohols and ketones which may ber produced include hexenol and hexenone; the various isomeric methyl, ethyl-, etc., hex-enols and hexenones; heptenol, heptencne and the various alkyl substituted heptenols and heptenones; higher molecular weight olenic alcohols and ketones including octenol, octenone, nonenol, nonenone, decanol, decanone, and the alkyl substituted derivatives of these alcohols and ketonessuch as the Various isomeric methyl-octenols, methylnonenones, methyl-ethylnonenols, etc.

The above disclosed alcohols may be used singly or mixtures of two or more of these alcohols may be reacted with phosphorus pentasulde or phosphorus pentoxide and the resulting reaction product reacted with a polyvalent metal or metal oxide to produce a desirable lubricating oil addition agent. Moreover, the ketones listed above may be reduced to the corresponding alcohols and these alcohols may then be employed as above indicated in the production of lubricating oil addition agents. l

Hydrocarbons or hydrocarbon fractions such as those specied hereinabove may be oxidized in the liquid phase by blowing or otherwise contacting them with oxygen, air or other oxygencontaining gaseous mixture. The liquid hydrocarbon is maintained at a temperature and a pressure high enough to cause oxidation to occur. We may oxidize at temperatures in the order of from about 100 F. to about 500 F. although we prefer to carry out the treatment at temperatures in the order of from about 200 F. to about 350 F. Pressures in the order of from about normal atmospheric pressure to about 300 pounds per square inch gage may be employed, although we prefer to eiect the oxidation at gage pressures in the order of from about to about 150 pounds per square inch. The temperature and pressure selected for oxidation will vary with the compound being treated and in general the tempera'- ture used will be as low as can be successfully employed to cause the oxidation reaction to proceed at an economical rate. This general rule is followed because it is found that the use of lower temperatures reduces the amounts of secondary oxidation products for a given quantity production of primary oxidation products and also re- Moreover, the pressures em- 'general it is desirable that the pressure be great enough to prevent the ready volatilization of the hydrocarbon stock being oxidized, thus minimizing the required condenser and cooler capacity required to strip liquid products from the exhaust gases leaving the oxidizer.

We may carry out the oxidation without the aid of oxidation catalysts since, in general, liquid phase oxidation of hydrocarbons of the types disclosed hereinabove occurs readily in the absence of catalysts. However, we may employ catalysts to increase the rate of oxidation, to permit the use of lower temperatures and/or pressures which would otherwise be required, or to direct the course of the oxidation reaction. Solid catalysts which are supported in the oxidation vessel are desirable since they do not complicate the separation of partial oxidation products from unoxidized hydrocarbons and are not removed frm the oxidation vessel along with portions of the partially oxidized hydrocarbon charge which are withdrawn and treated for the removal of partial oxidation products. Catalysts vwhich are useful in our process include those oxidation catalysts comprising metals lof the series having atomic numbers to 30, inclusive, i. e., calcium, scandium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, and zinc as well as the metals magnesium, aluminum, molybdenum, silver, tin, tantalum, cerium, neodymium, platinum, thorium, and uranium. By the term oxidation catalysts comprising metals we also intend to include compounds of these metals such as oxides and salts, such as the chlorides, bromides, iodides, nitrates, sulfates, sultes, phosphates, phosphites, vanadates, titanates, chromates, bichromates, molybdates. tungstates, uranates, etc. These metals, metal oxides or salts may be used as such or they may be distended on or impregnated in supports, said supports being materials such as pumice, silica gel, kaolin, kieselguhr, fullers earth,4 alumina, magnesia, asbestos fiber, etc. Also, combinations of two or more of the above metals, metal oxides, or salts may be used as the catalyst. In some instances it is desirable to employ a soluble or homogeneous catalyst which would be particularly active in initiating the oxidation and in such instances an organic salt of the above disclosed metals may be employed. Thus calcium, magnesium, iron, etc., naphthenates are active oxidation catalysts. Moreover, we may prefer to use an oxidation initiator, such as a peroxide, as for example, benzoyl peroxide, nitrogen peroxide, hydrogen peroxide, etc.

The treatment of a hydrocarbon or hydrocarbon-mixture for the production of partial oxidation products is desirably carried out in the equipment illustrated in the drawing. A column I, consisting of any typeof column or vessel suitable for liquid phase oxidation, which if desired,

may contain packing material, plates or trays,`

baliies, or other means of increasing the contact between the hydrocarbon material and the oxygen or oxygen-containing gas and which is arranged for heating and cooling, as by means of steam and water in internal coils, is maintained at a pressure between about normal atmospheric pressure and 300 pounds per square inch gage.

Oxygen, air or other oxygen-containing gas is introduced through valved inlet 2 and exhaust gases and vapors escape through outlet 3. Partially oxidized hydrocarbon material together with unoxidized hydrocarbon material is withdrawn from the bottom of the oxidizer through line 4, the rate of flow being controlled by valve 5, and passed to fractionating column 6 containing packing material or plates or other means of aiding fractionation and having a reboiler 1 to supply the heat required for fractionation. Column 6, together with its essential appurtenances constitutes the stripping section and this section and its operation may be varied as indicated hereinbelow. In those cases in which fractional distillation is employed as the means of effecting the separation o f oxygenated molecules, i. e.,products of partial oxidation, from unoxidized hydrocarbon molecules and oxygenated degradation products which boil at temperatures at or below the boiling point or boiling point range of the hydrocarbon feed, column 6 is maintained at any desirable pressure between about 29 inches of mercury vacuum and 300 pounds per square inch gage. In these cases, the products of partial, oxidation are removed from the bottom of column 6 through valved outlet 8 and the unoxidized hydrocarbon materials, together with degradation products, pass as vapors from the top of the column through line 9 and condenser I0 where the vapors are condensed and the condensate passes into reflux drum II. A portion of this liquid is returned as reflux to the top of column 6 through line I2, the rate of ow through this line being controlled by valve I3. valved line I4 carries liquid products from reux drum II to pump' IS-and thence to the oxidation column I. New feed enters the system through valved line I 6 leading into line I4. Exhaust gases and vapors leaving the oxidation vessel through line 3 are passed through condenser I1 into separator I8 from which the uncondensed gases escape through line I9 and pressure control valve 2li.v The liquid in vthis separatorv separates into two phases, an

aqueous phase containing low molecular Weight fatty acids, aldehydes and other preferentially water-soluble oxygenated products and a hydrocarbon phase containing in addition to unoxidized hydrocarbons, oxygenated degradation products which are preferentially soluble in the hydrocarbon phase. The aqueous phase is removed through valved outlet 2|. The hydrocarbon phase in separator I8 may be returned directly to column I through valved outlet 22, or it may be transferred through valved line 23 to a fractionating column 24 which is heated by means of reboiler 25 and operated under atmospheric or higher pressures, in which column the liquid product, separated from the exhaust gases and vapors from the oxidation column, is fractionated to separate as a bottoms fraction, unoxidized liquid hydrocarbons which are returned through line 26 and by means of pump 21 to the oxidation column and as overhead distillate the oxygenated degradation products, said distillate being passed from the top of column 24 through line 28, condenser 29 and into reux drum 30. A portion of the condensed overhead is returned as reflux through line 3| and valve 32 to fractionating column 24. Oxygenated degradation products are produced through line 33 and control valve 34. A valved inlet line'35 leading to the top of fractionating column `Ii may be used as an inlet line for new hydrocarbon feed or, as described hereinbelow, may be used as an inlet line for solvent in cases in which extractive distillation is employed to aid in the separation of the oxygenated products and unoxidized hydrocarbon material.

Although the oxidation equipment illustrated irf'tii drawinland described above shows the use^offfractional'distillation 'as the meansof separatingjor stripping the products of partial oxida fon from the' unoxidized hydrocarbon we v mPfY-,mplvyother-means of vcarrying out this separation., suchas those"indicatedhereinabove. 'lhus the fractionating` column 8 inthe drawing may b'e'used esj an extractive distillation column.

't in such cases, a solvent which preferentially disolves' the oxidized moleculesis Dumped into the Y 'f-tjop of the column throught/awed une 35 and fiowsdownward through the column contacting -leaving the solvent as bottoms.

.bop oircolumn fthe"vapors*,asoending thegcolumn and extracting therefrom the partially oxidized hydrocarbon molecules.ML Thes'olv'ent, containingthe productsy of linertial oxidation, 1s withdrawnas` bottoms from column 6 through valved outlet 8. This mixture is then pumped to a fractionating column (not shown in the drawing) Where the partial oxidation products are distilled overhead The bottoms from this'column `is returned as solvent to the @/Solvents which are useful in segragating the products vof ypartial oxidation from the unoxidized hydrocarbons in the extractive distillation of the mixture of these two componentsv include monhydroxy alcohols, such as ethyl, propyl, isop pmpyrahd higher mo1ecu1ar weight normal and j ',isomeric alcohols; polyhydroxy alcohols, such as vminion di-l tritetra-,'etc., ethtylene gylcols;

the others of these ethylene glycols, such as .Y monomethyl, monoethyl, monobutyl, etc., ethers l of mono-,'r di-., tri-', etc., ethylene glycols; the

estersof' these ethylene glycols, and theesters 5.1' of the` ethers oi' ethylene glycols, such as for examplepthet acetate of the monomethyl ether j of ethylene fglycol, propyleneglycols and the ether's of 'propylene glycol'sfthe esters of the .et/hers offpropylene slycols, including propylenel -f glycol and dipropylene glycol; polyhydroxyA alcohols including the trihydroxy and tetrahydryoxy alcohols, such as glycerine and erythritol; hydroxy amines such as ethanolamlne, diethanolamine, triethanolamine; halohydrines such as glycolchlorohydrine; amines, suchas butylamine, triethylamine and diamines, such as ethylenediamine; aliphatic ketones, suchy 'as methylethyl ketone, di'ethyl ketone, methylisopropylketonaetc.. diacetyl and acetonyl acetone;v cyclic ketones, such asl cyclopentanone, cyclohexanone, methylcyclohexanone and meth ylphenyl ketone; phenolic compounds, such `as phenols,v naphthols, cresols, xylenols, lthymol, etc.; polyhydric phenols, such as resorcinol, py-

lated` polyhydric phenols, such as 1-methyl-2,l 3-

.55 ,rocatechol pyrogallol, phloroglucinol, etc.; alkyl dihydroxy benzene, etc.; saturated heterocyclic compounds havingfive or six membered rings in Whichat leastfone of Ithe' atomsfin the ring is oxygen, nitrogen or sulfur, `such as Voxolane, thio1ane,vdoxolane, dioxane, oxane, piperidine,

morpholine, dithiane, etc.; derivatives of` such five and 'six membered heterocyclic ring compounds, such as` N-ethylpyrolidine,` tetrahydro'f f urfuryl alcohol, dibutanol, N-ethylipiperidine,

N-meth-yfmorpholine, N-phenylmorpholine, etc.; f nitroparailins,` such as.. nitromethane, Initroethane, `l,2l-dinitropropane, nitrobutanes, nitropentanes, etc.; nitro alcohols, such as-Z-nitro-l.-

ethanol,"2 and l3-nitro-l1-propanoh' etc., 4 they Y, nitro derivatives of unsaturated aliphatic'hydrocarbons, such as nitroethylene .and nitr'opropylene; the halogenatedv derivatives of the aforementioned nitx'oparailins and nitroalcohols, such as chloronitromethane, l'l-chloro-l-,-nitroethane,

etc., lnitro', aromatic compound;suchl yas nitrobenzene, nitrotoluenes, nitroxylenes, etc.;'A and alkyl nitrite's including the lnormal and isomeric nitrites from butyl to octylnitrite.

Y The choice of solvent to \,be,emp1oyed"w'ill`gen erally depend upon the characteristics of the hydrocarbon stock being oxidized and upon the characteristics of the partial oxidation products being separated since it is preferable that thev solvent does notform an azeotrope with the unoxidized hydrocarbon stockunder the conditions'. of operation and it is preferable that the solvent' have a boiling point at least 50S1 F. and'pr'eferably more than 75 F. above theboiling point of theI hydrocarbon stock being treated. Itis desirable' also thatthe boiling point of the solvent be sufficiently different from the boiling Ipoint or boiling point range of the partial' oxidation product that it'may be separatedtherefrom by fractional products are dissolved by the solvent and sep-1 f arated as an extract phase which is subsequentlyl fractionally distilled` to segregate the oxidation lproducts and the solvent,. andthe unox'idized hydrocarbons or raflinate phase may -be returned to the oxidizer directly or after fractionally vdistilling or otherwise treating it to remove small quantities of solvent. In addition to the solvents disclosed above we may employ aqueous solutions of mineral acids such'as sulfuric acid, sulfurous acid, nitric acid, hydrochloric acid, phosphoric acid, etc., as the solvents to eiect the sep-` aration of oxidized products from the unoxidized hydrocarbons. The addition of about 2 to livoi-v umes of water to the aqueous mineral acid solution of alcohols and/or ketones causes the sep-V arationl ofthe alcohols and/orketones' as anup- .I

pellphasewhich is substantially insoluble in the diluted mineral acid phase l and which maybe -decanted from the latter phase. -Forv example,.

65% sulfuric acid is an excellent selectivesolvent for Jthe primary oxidation products `obtained i our partial ,oxidationl process.. y; We may employ azeotropicdistillation ,to separate the unoxidized ,hydrocarbons from the products of oxidation using fractionating column 6 in' the drawing as the azeotroping column. This method is desirably employed in those. cases in which the products'of oxidation boil at ory near the boiling .point of the hydrocarbon being, oxidized. The compound selected as the azeotrope former forms a minimum boiling point azeotrope with the unoxidized hydrocarbons and thus facilitates the separation vof said lhydrocarbons from the oxidation products. Azeotrope formers which may be employed may be selected from the list of solvents disclosed hereinabove for use in extractive distillation processes.l In'selecting the particular azetrope former to'use in a specific' ycase it is. important that the boiling point of Y the solvent used as azeotrope former is not more than 50 F. and preferably'not morey than about 20". F. abovethe boiling pointof'the hydrocarbon w In carrying out the azeotropic distillation the azeotrope former is mixed with the feed to the ll fractionating column 6 in line 4 in a suilicient quantity to distill overhead all of the unoxidized lhydrocarbon together with said azeotrope former leaving the oxidized products as bottoms. substantlally free of unoxidized hydrocarbon and azeotrope former. The overhead distillate or azeotrope is withdrawn from reflux drum II, f

through line I I and valved line 36 to an azeotrope former recovery unit Where the azeotrope former is separated, as by solvent extraction, from the unoxidized hydrocarbon. The separated unoxidized hydrocarbon is returned to the oxidizer through valved inlet I6 to line I4. and pump I5. We may also use an adsorption process for the removal of partial oxidation products from the mixture of unoxidized and oxidized hydrocarbons oxidized products is discharged from the percolator and returned to the oxidizer for further treatment. Two percolators containing an adsorbent are connected in parallel so that one may be used for adsorbing oxidation products while the spent adsorbent in the other percolator is being treated for the recovery of adsorbed products and otherwise regenerated. Regeneration of the spent adsorbent may be accomplished by a steam stripping operation in which steam or superheated steam is blown through the pervcolator, after rst draining all of the unoxidized hydrocarbon from the unit, and the steam containing the oxidation products is condensed and cooled and passed through a separator vessel where the aqueous phase is separated from the oxidation products,

The c rude partial oxidation product, which may be stripped from its mixture with unoxidized hydrocarbon leaving the bottom of the oxidizer by any ofl the above mentioned processes, consists primarily of molecules having the same num# ber of carbon atoms as the parent hydrocarbon and containing one atom of oxygen. product comprises alcohols. ketones, or mixtures of alcohols and ketones, which may be produced by a primary oxidation reaction involving only the addition of one atom of oxygen per molecule. Thus, for example, the partial oxidation of methylcyclohexane proceeds in the manner illustrated by the following equations:

CgaO/H Cxo OH 3.o/ \om o o/ \om mo on. mc H,

Hl Ha Methylcyclohexane l-methylcyclohexanol CH; H

\C HzC/ \CBI: j!) Bra |J\ ./H M01 -e CHx- -CHz-CHx-CHa-CIIa-CH:

Methylcyclohexane 2-heptanone In the ilrst reaction the oxygen atom enters the molecule at the tertiary carbon atom and the tertiary hydrogen atom attaches itself to the This r 12 oxygen forming a cycloaliphatic alcohol. In th second reaction the oxygen atom replaces the tertiary hydrogen and in this case the ring'breaks at position 1, the tertiary hydrogen atom shifting to the end carbon atom of the carbon chainv and the reaction results in the formation of an acyclic aliphatic ketone.

Other types oi ketones which may be produced by partial oxidation and which may be present in the oxidized product together with the alcohols and ketones ofthe types noted above are the cycloaliphatic ketones. These compounds are produced by the reaction between one molecule of oxygen and one molecule of the hydrocarbon and this type of reaction maybe represented by the following equation:

In this case one atom of oxygen replaces the two hydrogen atoms attached to one of the carbon atoms forming a cyclic ketone and the thus freed hydrogen atoms combine with the second oxygen atom to form water.

The proportion of alcohol to ketone in a given partial oxidation product will depend upon the particular hydrocarbon being oxidized, the catalyst employed, and upon the temperature and pressure maintained in the oxidizer and may therefore be varied within certain limits by changing the hydrocarbon feed and/or the conditions of treatment. vThus the controlled partial oxidation of methylcyclohexane at relatively low pressures and temperatures results in the production of approximately equal quantities of methyl"- cyclohexanol and 2heptanone, whereas the oxlv dation of 1,3-dimethylcyclopentane under similar conditions of temperature and pressure results in the formation of large proportions of -methyl hexanone2 and relatively small proportions oi 1, 3-dimethylcyclopentanol.

In those instances in which alcohols are the desired products and mixtures of alcohols and ketones are obtained as products of partial 0x1-, dation the ketones may be reduced to the corresponding alcohols. This reduction may be carried out on the mixtures of alcohols and ketones and in this instance the resulting alcohols would be a mixture of cyclic and acycllc alcohols, or the crude product may nrst be separated into a ketone fraction and an alcohol fraction by fractional distillation or by a chemical treatment as indicated hereinbelow and the ketone fraction subsequently reduced to the corresponding alcohol. The reduction may be carried `out by any of the well known processes for reducing or hydogenating organic compounds, such as hydrogenaat about 315 E. and 2heptanone which boils at t 2,456,oe2 l e 302 F. These compounds can be separated by careful fractional distillation. Improved separation by fractional distillation may often be realized by carrying out. the distillation at reduced pressures, i, e., under a vacuum, or at pressures greater than atmospheric pressure because the vapor pressures of the alcohol and ketone components do not change to the same extent with changes in distillation pressure and thus the spread between the boiling points of the two components usually becomes greater with changes in pressure, often allowing separation of components which boil at the same temperature under ordinary atmospheric pressures.

Chemical methods of separation, wherein a chemical reagent is caused to react, or form an addition compound with one of the components of the mixture, may also be employed. For example, the product of partial oxidation may be washed with a concentrated aqueous solution of sodium bisulte which forms an addition product with the ketone. The alcohol which is unaected by this treatment may then be decanted from the aqueous solution of the ketone addition compound and then decomposed as by warming with alkalis, such as dilute sodium hydroxide or with an acid, such as dilute sulfuric acid, releasing the ketone which may be decanted from the remaining aqueous phase. The alcohol and the ketone may be further puried by fractional distillation.

In those cases in which more than one alcohol and/or more than one ketone is formed by the oxidation reaction, as for example, when the hydrocarbon feed to the oxidizer contains more than one naphthene hydrocarbon, the ketones may be separated from the alcohols, as indicated above, and the separated components may then be fractionally distilled to separate individual alcohols and/or ketones in those cases in which the boiling points of the individual alcohols and ketones are sufficiently far apart to allow such separation to be made. However, in many instances it is not essential that the alcohol component be separated into individual compounds since mixtures of alcohols such as are produced in our process are entirely satisfactory for most of the uses indicated hereinabove. mixtures of ketones of similar types may be reduced to the corresponding alcohols and the thus produced mixture of alcohols may be employed without further separation. l

The following specific examples further ilustrate the invention.

Example I Methylcyclohexane was pumped into the oxidation column, heated to a'temperature of 250o F. and maintained at a pressure of about 90 pounds per square inch gage. Air was introduced at the bottom of the vessel at the rate of 65 cubic feet per barrel of methylcyclohexane per minute for` a period of about 20 minutes until analysis of the oxidation charge showed the presence of one atom of combined oxygen per 200 molecules of methylcyclohexane. At this time fresh feed was started into the oxidizer at a rate such that the liquid level in the oxidizer remained constant throughout the operations described below. Partially oxidized methylcyclohexane was removed from the bottom of the column and transferred Moreover,

to a fractionating column maintained at normal atmospheric pressure and a temperature such that the temperature in the vapor line leading from the top o f the column was 21.25 F. Un-

oxidized' methylcyclohexane distilled overhead from this fractionating column and was condensed and returned to the oxidizer for further oxidation and oxidized products were removed as bottoms from the fractionating column, said oxidized products being further treated as described herelnbelow. Exhaust gases and vapors leaving the top of the oxidation column were passed through a condenser and into a separator. The condensed liquid being returned directly to the oxidizer'and the uncondensed gases, consistting primarily of spent air, were vented to the atmosphere.

The oxygenated product obtained as bottoms from the fractionating column consisted primarily of a mixture of equal parts by weight of 1-methylcyclohexanol and 2-heptancne. A portion of. this mixture was extracted with a saturated aqueous sodium bisuliite solution to separate the Z-heptanone, as an 'addition product with the sodium bisulfite, from the l-methylcyclohexanol. The extracted cyclohexanol was subsequently fractionally distilled at reduced pressure to produce a substantially pure l-methylcyclohexanol as a heart cut boiling between 160 F. and 166 F. at 22 mm. of mercury pressure. The bisulte addition product with the ketone was decomposed by treatment with dilute sulfuric acid, the freed ketone was separated by decantation from the aqueous layer, Washed with additional quantities of water and nally fractionally distilled to produce a heart cut boiling between 300 F, and 304 F. at normal atmospheric pressure and consisting substantially of pure Z-heptanone. This latter fraction was reduced to the corresponding alcohol, Z-heptanol, by hydrogenation over a nickel catalyst at 300 F. and 400 pounds per square inch pressure for a period of 4 hours.

A second portion of the oxygenated product obtained as bottoms from the fractionating column and comprising a mixture of l-methylcyclohexanol and 2-heptanone was hydrogenated in the manner indicated above for hydrogenating the separated 2-heptanone. The product cornprised a mixture of l-methylcyclohexanol and Z-heptanol.

To illustrate one use of the alcohols prepared as above, to 1.57 grams of the 1-methylcyclohexanol, the 2-heptanol, or the mixture of these alcohols, is added 222 grams of powdered phosphorus pentasulde and the mixture is agitated and heated to 275 F. for a period of three hours at which time the phosphorus pentasulde has completely dissolved. To the resulting solution is added 82 grams of zinc oxide and the agitating and heating is continued for an additional four hours at which time the product is iiltered hotJ (275 F.) to remove small amounts of unreacted zinc oxide. This product may be added to an SAE 30 highly solvent refined Western lubricating oil having Saybolt Universal viscosities of 540 seconds at F. and 64 seconds at 210 F. and a viscosity index (Dean and Davis System) of 90, in the ratio of about 1 part by weight of the zinc salt to 99 parts of the lubricating oil and the resulting mixture heated to about 250 F. and agitated until the zinc salt is dissolved and thoroughly mixed in the oil to produce a lubricating oil composition which is a particularly desirable lubricant for internal combustion engines. This lubricating oil composition possesses improved film strength, X"anti-corrosion and detergency characteristics.y Also, 1 part of the above described zinc salt may be blended in a similar manner with 1 part of the calcium saltl of oil- 15 soluble petroleum sulfonic acids produced by treating petroleum with strong sulfuric acid and 98 parts of the above mentioned highly solvent v rened Western lubricating oil to produce a lubricating oil composition having high film strength andanti-corrosion characteristics and particularlyhigh detergency characteristics.

Example II A naphthenic fraction of petroleum boiling' between 192 F. and 198 F. prepared by careful fractionation of a straight run gasoline derived from a highly naphthenic crude oil and containing about 50% by volume of a mixture of dimethylcyclopentanes was charged to the oxidation column, heated to 250 F. and maintained at a pressure of 60 pounds per square inch gage. Air was introduced into the oxidation column at a point near the 'bottom of the column at the rate of 65 cubic feet per barrel of charge per minute and exhaust gases and vapors were led from the top of the column through a condenser and into a separator from which condensed liquid owed by gravity back into the oxidizer and uncondensed gases were allowed to escape to the atmosphere. The air blowing was continued for a period of approximately-20 minutes at which time analysis of the liquid in the oxldizer indicated the presence of approximately 0.5% of molecules containing oxygen. At this time fresh feed was pumped into the oxidizer at such a rate that the liquid level in the column remained constant throughout the following operations. The slightly oxidized hydrocarbon fraction was withdrawn from the bottom of the oxidizer and transferred to a fractionating column maintained at normal atmospheric pressure and at a temperature such that the vapor leaving the tiop of the column had a temperature of 198 F. This overhead vapor consisting of unoxidized hydrocarbon material was condensed, part of the condensate being returned to the fractionating column as reflux and part of it being pumped back into the oxidizer along with the new hydrocarbon feed referred to above.

Products of partial oxidation were withdrawn as bottoms from the fractionating column, and

transferred to a second iractionating column from which a fraction boiling between about 284 F. and 302 F. was produced. as a side cut. This fraction, which amounted to about 50% by volunie of the oxidized fraction obtained as bottoms from the rst frationating column comprised a mixture of aliphatic ketones having seven carbon atoms per molecule. The overhead from the second fractionating column contained lower boiling alcohols and ketones, i. e., having fewer than seven carbon atoms permolecule, and the bot toms from this column contained a mixture of dimethylcyclopentanols and higher molecular weight alcohols and ketones together with oxygenated polymerization products.

The mixture of -aliphatic ketones boiling between about 284 F. and 302 F. was reduced to a mixture of the corresponding alcohols by liquid phase hydrogenation with gaseous hydrogen over a nickel catalyst at 300 F. and 400 pounds per square inch gage for a period of four hours. The hydrogenated product was fractionally distilled and the mixture of alcohols obtained as a heart cut boiling between about 293 F. arid 311 F. The yield of alcohols amounted to about 90% by volume of the mixture of ketones. A

To illustrate one of the uses of the mixture of alcohols prepared 'as indicated above, to 465 grams of the alcohols is added 222 grams of phosphorus pentasulilde and the mixture is agitated and heated to 275 F. for three hours. To this product is then added 82 grams of zinc oxide and the heating and agitating continued for an additional four hours at which time the hot product is filtered to remove any unreacted'zinc oxide. The resulting 'zinc salt may be blended with the lubricating oil described in Example I in the ratio of about 1 part of the zinc salt to 99 parts of the lubricating oil, or 1 part of the zinc salt may be blended with 1 part of a calcium salt of oil-soluble petroleum sulfonic acids and 98 parts of the same lubricating oil to produce lubricating oil compositions having high iilm strengths, anti-corrosion and detergency characteristics which are desirable features of lubricants for internal combustion engines and particularly Diesel engines. In each of the above instances the blending may be accomplished by heating to about 250 F. and agitatlng the ingredients until the added salts are completely dissolved and mixed in the lubricating oil.

The foregoing description and examples are not to be taken as in any way limiting but merely illustrative of our invention for many variations may be made by those skilled in the art without departing from the spirit or scope of the following claims:

We claim:

1. A process for producing a lubricating oil addition agent comprising the partial oxidation of a non-aromatic cyclic hydrocarbon by contacting said hydrocarbon with an oxygen containing gas at temperatures in the order of from about 100 F. to about 500 F. and at pressures in the order of from about normal atmospheric pressure to about 300 pounds per square inch gage to produce partial oxidation products containing the same number of carbon atoms per molecule as said non-aromatic cyclic hydrocarbon and containing one atom of oxygen per molecule, reacting said partial oxidation products with a phosphorus compound selected from the class of phosphorus compounds comprising phosphorus pentasulde and phosphorus pentoxide to form phosphate esters and reacting said phosphate esters with the oxide of a polyvalent metal.

2. A process for producing a lubricating oil addition agent comprising airblowing a nonaromatic cyclic hydrocarbon at temperatures in the order of from about 100 F. to about 500 F. and at pressures in the order of from about normal atmospheric pressure to about 300 pounds per square inch gage to produce a mixture of alcohols and ketones containing at least ve carbon atoms per molecule, hydrogenating said mixture of alcohols and ketones to produce a mixture consisting primarily of alcohols, reacting said mixture of alcohols with a phosphorus compound selected from the class of phosphorus compounds comprising phosphorus pentasullde and phosphorus pentoxide to produce the corresponding phosphate esters of said mixture of alcohols, reacting said phosphate esters with the oxide of a polyvalent metal selected from the class of metals consisting of zinc,lead, aluminum, magnesium, barium and strontium to form the corresponding polyvalent metal salts of said phosphate esters.

3. A process for producing a lubricating oil addition agent comprising partially oxidizing a hydrocarbon fraction containing at least one non-aromatic cyclic hydrocarbon by contacting said hydrocarbon fraction with air at a temperature in the order of from about 200 F. to about' ing oxygen, maintaining said proportion of mole-A cules containing oxygen by removing portions of said partially oxidized hydrocarbon fraction from the oxidation Vessel and stripping from said partially oxidized hydrocarbon fraction said molecules containing oxygen and comprising alcohols and ketones, returning unoxidized hydrocarbon to said oxidation vessel, separating said molecules containing oxygen into one fraction comprising alcohols and a second fraction comprising ketones, hydrogenating said fraction comprising ketones to 'form the corresponding alcohols, combining the thus formed alcohols with said fraction comprising alcohols, reacting the resulting mixture of alcohols with phosphorus pentasulde tosjorm the corresponding thiophosphate estes,`and reacting said thiophosphate esters wtih the oxide o! a polyvalent metal selected from the class of polyvalent metals consisting of zinc, lead, aluminum, magnesium. barium and strontium.

ADALBERT FARKAS. ARTHUR F. STRIBLEY, JR.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS Number Name Date 1,893,018 Christmann Jan. 3,' 1933 1,939,951 Buchanan Dec. 19, 1933 2,175,509 Rogers Oct. 10, 1939 l5 2,226,552 `Conary Dec. 31, 1940 2,228,658 Farrington Jan. 14, 1941 2,242,260 Prutton May 20, 1941 2,252,984 Rutherford Aug. 19, 1941 2,252,985 Rutherford Aug. 19, 1941 2o 2,261,047 Assen Oct. 28, 1941 2,285,853 Downing June 9, 1942 2,285,854 Downing June 9, 1942 2,310,175 Farrington Feb. 2, 1943 2,344,988 Kavanagh Mar. 28, 1944 25 2,369,632 Cook Feb. 13, 1945 

